The national registry is a database of HLA markers from thousands of people. While some get lucky and fin a match, many do not. They might wait months for a suitable donor to be entered in the database, and then it might be too late.
Joining the registry is easy. You register online and they mail you a cheek swab kit. Donating is either PBCS, which is similar to a blood donation, or a regular marrow donation, which is an outpatient procedure. There are minimal risks, and you will be saving someone's life.
Don't want to join the registry, or can't due to a medical condition? The processing of each donor kit costs about $100. With your donation, you can help grow the donor registry.
learn more a bout Bone marrow donation here.